1. Field of the Invention
The invention relates to a virtualization technique of a computer system, and more particularly, relates to a system and a method for managing an expansion read-only memory (expansion ROM) that supports a virtual function (VF) and a management host thereof.
2. Description of Related Art
In recent years, due to the rapid progress in the development of the Internet, users have higher demands for information services, which imposes a heavier burden on a server. Therefore, in order to reduce costs and efficiently use resources, server virtualization technology has gradually become the trend. In terms of the specification of PCIE (peripheral component interconnect express), single root I/O virtualization (SR-IOV) is one effective solution for server virtualization. The SR-IOV technology allows a physical host (e.g. computer host) to assign virtual functions (VF) to different virtual machines.
On the other hand, because an operating system can be stored in a variety of storage media (e.g. hard disc, network server, compact disk-read only memory (CD-ROM), etc.), the physical host provides various boot options for the user to load the system. For example, an expansion read-only memory base address register (expansion ROM BAR) in a physical function (PF) of a device that supports the SR-IOV technology, e.g. network adapter, is provided with a memory mapped input output (MMIO) address for accessing the content of an expansion ROM, and this contact supports a program or kernel of a preboot execution environment (PXE). The physical host needs to obtain the program content of the PXE, so as to acquire the operating system required for booting through the network. However, the expansion ROM BAR in the virtual function of the device that supports the SR-IOV technology is reserved. For this reason, PXE boot is not available.